Method and apparatus for treating produce



2 Sheets-Sheet 1 .M n Q A R II I I l n m o |||i 1 l l wa w WNW IIWIWI l-| II a. 8 N A 1 I l l I l I I I I I I l l I l II I w W T m. u n mm 1 Feb. 1, 1955 E. B. HAMM METHOD AND APPARATUS FOR TREATING PRODUCE Filed Dec. 15, 1951 Feb. 1, 1955 E. B. HAMM 2,701,201

METHOD AND, APPARATUS FOR TREATING PRODUCE Filed Dec. 15, 1951 2 Sheets-Sheet 2 IN VEN TOR. EDWIN B. HAMM A 7' TOR/VE Y METHOD AND APPARATUS FOR 'EREATENG PRODUCE Edwin B. Hamm, Pasadena, Calif., assignor tov Wallace &

Tiernan Products Corporation, Belleville, N. 1., a corporation of. New Jersey Application December 15,. 1951, Serial No. 261,900 (llai'ms; (Cl. 99-403) This invention relates to. produce treating apparatus and particularly to apparatus for intimately contacting packaged produce with a liquid: treating bath. Although in no way limited to such use, the invention is described with relation to the germicidal washing of melons, this being a presently practiced. application of the described apparatus.

Melons as well as many other fruitsand vegetables are susceptible to mold and bacterial spoilage during shipment and storage. The. organism responsible. for such spoilage may be. on the produce as received. at the packing plant or inoculation may take. place as a result of bruising and contact of. healthy fruit with infected fruit during packing operations. Considerable. effort has been made to minimize spoilage by suitable germicidaltreatment of such produce prior to, during or subsequent to packing. These treating. procedures. naturally divide themselves into three categories, namely gas exposure,

wax coating, and washing The present invention. relates to apparatus affording the improvements int-he. germicidal Washing, of produce susceptibleto mold and. bacterial spoilage and. also compatible toliquid washing. Melons are an example of produce of. this type.

Heretofore, melons have been washed with. germicidal solutions prior to packing by immersion in a liquid bath and in unconfined condition. Germicidal. agents employed for this purpose include borax, hypochlorite and the like. Immersion or washing prior to packing has several inherent disadvantages which mitigate the beneficial. effect of the treatment. From the washing standpoint, handling of the free melons is= diflicult and. interferes with smooth and rapid operation of the packing line. In addition, the washed melons must be handled when wet subsequent to the washing; procedure, which is objectionable in itself. and. which also presents opportunity for inoculation after treatment as a consequence of the inevitable bruising attendant upon handling. Furthermore, treatment prior to sorting and packing; involves useless. consumption of material in treating culls.

Ideally, the melons should. be treated after packing, at which time they are immobile with respect toeach, other and are not subject to further. individual handling. However, there has not been. satisfactory means of washing the packed fruit. I have now devised apparatus for washing produce in containers which overcomesv the inherent inelfectiveness of immersion or spraying.

To accomplish this objective I provide apparatus com prising an elongated open-ended housing of generally rectangular cross section, conveyor means. traveling through the housing, means connected to introduce a stream of treating liquid into the housing at a point or points between the open ends thereof, means for introducing packing containers at one end of the housing and means for withdrawing containers from the other end of the housing. The invention is suited for handling any type of produce container which is; sufiiciently open. to; give access to its contents; Since a conventional slatted crate is typical of such containers, the invention is hereinafter conveniently described with reference to this type of con tainer. The term housing as used herein includes any member having a bottom and sides irrespective of whether or not it is enclosed at the top. This definition encom passes a trough as well as a tunnel-like member.

In preferred practice a reservoir of treating solution 18 associated. with the housing and a pump circulates the fluid from. the reservoir through the housing. The crates .nited States Patent 0 2,701,201 Patented Feb. 1, 1955 may be passed throughv the. housing in end. to end abutment or in a. sideways manner and in. side abutment.

A. principal featurev of the invention is crate movement against what in effect is. a water barrier maintained in the housing, by the impedance to water flow presented by the crates themselves. As succeeding crates pass through this self-imposed water barrier, the water. filters with considerable turbulence throughout the contents of the crate to. penetrate. the smallest air pockets and interstices. The housing serves as. a two-sided flooding chamber with the crates passing. therethrough acting as. the other two sides. I melons passed through the described. apparatus are. uniformly and substantially completely surface wet.

The invention will. be more clearly understood from the following. detailed! description thereof taken in conjunction with the accompanying drawing in which;

Fig. l is a plan view of one embodiment of the apparatus of the invention;

Fig. 2 is a longitudinal sectional elevation taken' on the line 2--2' of Fig. l; and

Fig. 3 is. a transverse sectional elevation taken on the line 3-3 of Fig. 1

All of the figures of the drawing comprise difierent views of the same embodiment of the invention. Modifications thereof will become apparent as the description proceeds.

Referring to the drawing, the apparatus there shown comprises an open-ended housing 10 having substantially vertical side walls 11, 12,. a top 13 and a floor 14 forming an elongated open-ended tunnel or passageway preferably of rectangular cross section. The side walls 11 and 12 conveniently extend longitudinally beyond the top and floor members of the housing.

The housing 10 is mounted above a basin 16 which serves as a, reservoir for a body of liquid 18 and also as support means for the housing elevating it to a. level substantially conforming, to the height of a normal packing line. The housing. 1.0 is inclined upwardly from an inlet end to an outlet end as indicated by arrows in Fig. 2, showing, the direction of. crate travel through the housing. The entire housing need. not be upset as shown, it being entirely satisfactory if the floor alone is inclined. Moreover, inclination from inlet: to outlet, although preferred for reasons hereinafter apparent, is in no way a limitation of the process or apparatus of the invention.

A conveyor 20 is mounted to travel across the floor 14 of the housing from the inlet to the outlet end thereof and, like the housing. floor, is inclined upwardly in. the direction of travel. A pump 22 including a motor 23 and a standpipe. 24 is mounted to take suction on. the body of liquid in the basin or reservoir 16- and to discharge liquid through an outlet conduit 26 opening into the side wall 12 of the housing. 10'. Referring to Fig- 3 the conduit opens into the housing. at. a point above the top of crates passing through the housing, a crate 28. being shown. in this figure illustrating the relative sizes of the crate and the housing section. v The crate 2.8 is typical of the type used for this type of. produce, all sides thereof comprising parallel spaced slats- The apparatus is not limited to use with a solution reservoir and recirculating. pump. These refinements may be replaced simply by a hose adapted to discharge treating solution into the flooding. chamber intermediate its ends.

A feed conveyor 30 and a discharge conveyor 32 are provided respectively at the inlet and outlet ends of the housing, the conveyors 30 and 32 being conveniently roller conveyors as illustrated. The feed. conveyor. 30. connects with a series of idler rollers 34 mounted between the extending ends of the, housing sides 11 and I2 and forming with the feed conveyor 30 a continuous roller bed adjoining the end of the conveyor 20.

A detent switch 36 is mounted in the inlet conveyor 30 and is connected in circuit with the conveyor motor 21, pump. motor 23' and a time delay mechanism 31. The circuit arrangement is such that the conveyor motor 21 and pump motor 23 are energized only when the detent switch 36 is depressed by an overlying. crate; If crate flow is interrupted sothat: the" detent' switch is not sodepressed, the conveyor motor is. shut. oif and the It has been demonstrated. that crated' pump motor after a short time interval, as determined by the time delay mechanism 37, is likewise shut off. The reason for this control arrangement is that optimum operation of the apparatus, as will become apparent hereinafter, depends upon a continuous line of crates in end to end abutment passing through the housing.

Wipers 4-0 and 41 are mounted to the side members 11 and 12 respectively adjacent the inlet end of the housing to control Water flow from this end by means of a partial seal formed by the wipers with the sides of crates passing into the housing.

The operation of the device is as follows: As a line of produce crates approach the housing on the inlet conveyor 30, the detent switch 36 is depressed energizing the conveyor motor 21 and the pump motor 23, thereby initiating travel of the conveyor 20 and discharge of treating solution into the housing 10. As this line of crates continues on the conveyor 30, idler rollers 34 and conveyor 20 into the housing to the point of liquid inlet, treating solution is backed up ahead of the first crate in such volume as to overflow the top of the crate and around the sides thereof in the comparatively narrow region defined between the crate sides and the housing sides. As long as a continuous stream of crates is introduced into the apparatus, this condition continues so that as each crate passes through the housing a large volume of water circulates over the top, through the open front, and through the open sides of the crate, a portion thereof filtering downwardly through the crate to drain from the bottom thereof. The net eifect is a complete flooding of the contents of the crate with suflicient turbulence to insure adequate wetting of all of the surfaces of the produce confined therein. The treating solution escapes both from the inlet end, this being the downhill side of the housing, and from the outlet end due to the damming eflect of the crates passing through the housing to return to the basin 16 for recirculation.

The crates are conveniently treated in end abutment and the apparatus, as illustrated, is dimensioned accordingly. In some installations it may be desirable to pass crates through the flooding chamber in side abutment, which requires only an appropriate adjustment in cham her size.

In a typical operation, the conveyor 20 is driven at a speed of approximately 59 feet per minute and the treating solution is pumped at a rate of approximately 1000 gallons per minute at a four foot head through the port 27, it being possible under these conditions to treat at the rate of 28 cases per minute. Because of the time delay feature in the pump shut-off, a much smaller rate can be treated under the same conditions, as for example approximately six cases per minute. Periodic interruption of the crate travel due to release of the detent switch will not, unless of long duration, cause the pump to shut oif so that at all times there is a continuous flow of liquid into the housing and an uninterrupted line of crates at least from the detent switch through the housing. The fact that at this comparatively slow throughput crate travel may be intermittent is immaterial since extended residence in the housing merely further insures the complete wetting of the conten The turbulence developed in the apparatus of the invention not only has the advantage of insuring proper wetting of the produce but has the further advantage of enabling the use of germicidal suspensions as well as solutions. Such a suspension is maintained without auxiliary agitation by a virtue of the turbulence developed and maintained in the apparatus. An important feature of the invention, as above noted, is the means for insuring an uninterrupted line of crates in the housing. A gap in the feed line to the apparatus is, by means of the detent switch and associated circuit, converted into discontinuous travel in the housing but with the crates therein in abutment. A gap between crates in the housing is to be avoided as resulting in an undesirable lowering of the liquid level therein and bidirectional washing. Better surface wetting is achieved if the liquid level is maintained above the crates, which is accomplished by an unbroken line and if liquid contact is substantially all counter-current.

I claim:

1. A method of turbulently flooding produce in containers with a germicidal liquid which comprises passing the produce containers serially and in substantially abutting relation through an open ended treating region, introducing the germicidal liquid into the treating region whereby the containers successively traversing the adjacent open ends of the region act as partial liquid dams impeding the escape of liquid from the region, and controlling the rate of introduction of liquid into the region to at least approximately equal the rate at which the liquid escapes from the region around the sides of the containers successively traversing opposite ends of the region.

2. A method of turbulently flooding produce in containers with water which comprises passing the produce containers serially and in substantially abutting relation through an open ended treating region, introducing the Water into the treating region whereby the containers successively traversing the adjacent open ends of the region act as partial liquid dams impeding the escape of liquid from the region, and controlling the rate of introduction of liquid into the region to at least approximately equal the rate at which the liquid escapes from the region around the sides of the containers successively traversing opposite ends of the region.

3. A method of turbulently flooding produce in con-' tainers with a germicidal liquid which comprises passing the produce containers serially and in substantially abutting relation through an open ended treating region, introducing the germicidal liquid into the treating region from a body of liquid whereby the containers successively traversing the opposite open ends of the region act as partial liquid dams impeding the escape of liquid from the region, controlling the rate of introduction of liquid into the region to at least approximately equal the rate at which liquid escapes from the region around the sides of the containers successively traversing the opposite ends of the region, and returning the liquid escaping from the opposite ends of the region to the body of liquid for recirculation into the region.

4. Apparatus for turbulently flooding produce in crates with a liquid comprising an elongated open-ended housing of generally rectangular section and inclined upwardly from a feed end to a discharge end, conveyor means disposed along the floor of the housing, a motor for driving the conveyor in the direction of upward incline of the housing, a liquid reservoir, a pump including a pump motor connected to pump liquid from the reservoir into the housing between the open ends thereof at a rate at least approximately equal to the rate of liquid flow from the housing around the sides of the containers disposed therein, feed means for introducing containers at the said feed end of the housing and discharge means for receiving containers from the discharge end of the housing, a detent switch mounted in association with said feed means and actuated responsive to passage of containers over the switch, a time delay relay, the switch, conveyor motor, pump motor, time delay relay, and a source of power, being connected in a circuit whereby the conveyor motor is energized and de-energized immediately responsive to opening and closing of the detent switch and the pump motor is energized by the detent switch and de-energized by the detent switch With a time lag determined by said time delay relay.

5. Apparatus for turbulently flooding produce in crates with a liquid which comprises an elongated open-ended housing having parallel vertically disposed side walls and connecting substantially imperforate floor and cover means arranged in substantially rectangular section of slightly greater width than said crates and higher than said crates, conveyor means traveling along the floor of the housing for carrying crates in serial arrangement through the housing from one open end in substantially abutting relation whereby the crates successively located adjacent the open ends of the housing form with the housing a loosely constructed tank to the opposite open end, a liquid reservoir, pump means connected to pump liquid from the reservoir into the housing through a port located inwardly of the ends of the housing and above the tops of the containers passing therethrough, the pump being capable of delivering liquid from the reservoir into the housing at a rate at least approximately equal to the rate of liquid flow around the sides of the crates next adjacent opposite ends of the particular crate disposed in the vicinity of the port, and means for returning liquid from the housing to the reservoir for recirculation.

6. Apparatus for turbulently flooding produce in crates with ,a liquid which comprises an open-ended elongated housing having a substantially imperforate floor and defining a treating region inwardly of the open ends thereof, conveyor means for carrying crates continuously through the housing in serial substantially abutting arrangement whereby each succeeding crate travels through the treating region, means for introducing said liquid into the housing approximately in the vicinity of the treating region and at a rate at least approximately equal to the rate of liquid flow around the sides of crates next adjacent opposite ends of the treating region whereby the crates successively located adjacent opposite ends of the treating region define with the housing a loosely constructed tank forming the treating region and in which crates are turbulently flooded, and means for automatically stopping the conveyor and liquid flow responsive to any interruption in the continuity of the crates thereon.

7. Apparatus for turbulently flooding produce in containers with a liquid which comprises an open ended housing having a substantially imperforate floor and spaced vertical side walls, means for passing a plurality of the produce-containing containers through the housing in substantially abutting relation, the spacing between the side walls of the housing being greater but not substantially greater than the transverse dimension of the containers as they pass therethrough, means connected to continuously introduce the liquid into the housing between the open ends whereby the containers act as a partial liquid dam and the containers successively disposed adjacent the opposite open ends of the housing form with the floor and sides of the housing a loosely constructed tank which induces turbulent flooding of the intervening containers.

8. Apparatus for turbulently flooding produce in containers with a liquid which comprises an open ended housing having a substantially imperforate floor and spaced vertical side walls partially defining a treating region between the open ends of the housing, means for passing a plurality of the containers through the housing in substantially abutting relation, the spacing between the side walls of the housing being greater but not substantially greater than the transverse dimension of the containers passing th'erethrough, liquid injection means connected to continuously introduce the liquid into the housing between the open ends whereby the containers act as a partial liquid dam and containers successively disposed adjacent opposite ends of the housing form with the floor and side walls of the housing a loosely constructed tank forming said treating region, and means controlling liquid flow in said injection means to maintain the rate of such flow at least approximately equal to the rate of liquid flow around the sides of the containers successively disposed adjacent opposite ends of the housing whereby turbulent flooding of the containers in the treating region is obtained.

9. Apparatus according to claim 8 including a conveyor disposed adjacent the floor of the housing and extending from end to end thereof for continuously carrying crates in serial arrangement through the housing.

10. Apparatus according to claim 8 wherein the bottom of the housing is inclined upwardly from the end at which the crates are introduced to the end from which the crates are withdrawn to induce liquid flow countercurrently to the direction of travel of the containers.

References Cited in the file of this patent UNITED STATES PATENTS 1,426,142 Blakeslee Aug. 15, 1922 1,512,918 Forsgard Oct. 28, 1924 1,617,096 Bell Feb. 8, 1927 1,640,324 Hibbard Aug. 23, 1927 1,664,637 Merseles Apr. 3, 1928 1,917,350 Wolf July 11, 1933 2,103,842 Drake Dec. 28, 1937 2,282,187 Herold et al. May 5, 1942 2,549,216 Martin Apr. 17, 1951 2,574,058 Porter Nov. 6, 1951 2,622,608 Moore et al. Dec. 23, 1952 OTHER REFERENCES Popular Bulletin Number 142, July 1928, article entitled The Removal of Spray Residue From Apples and Pears in Washington State, by J. R. Magness et al., pages 9, 10 and 11.

Technical Bulletin Number 488, October 1935, article entitled Reducing Decay in Citrus Fruits With Borax, by J. R. Winston, pages 20 to 23, inclusive. 

1. A METHOD OF TURBULENTLY FLOODING PRODUCE IN CONTAINERS WITH A GERMICIDAL LIQUID WHICH COMPRISES PASSING THE PRODUCE CONTAINERS SERIALLY AND IN SUBSTANTIALLY ABUTTING RELATION THROUGH AN OPEN ENDED TREATING REGION, INTRODUCING THE GERMICIDAL LIQUID INTO THE TREATING REGION WHEREBY THE CONTAINERS SUCCESSIVELY TRAVERSING THE ADJACENT OPEN ENDS OF THE REGION ACT AS PARTIAL LIQUID DAMS IMPEDING THE ESCAPE OF LIQUID FROM THE REGION, AND CONTROLLING THE RATE OF INTRODUCTION OF LIQUID INTO THE REGION TO AT LEAST APPROXIMATELY EQUAL THE RATE AT WHICH THE LIQUID ESCAPES FROM THE REGION AROUND THE SIDES OF THE CONTAINERS SUCCESSIVELY TRAVERSING OPPOSITE ENDS OF THE REGION. 